/*
 * Copyright (C) 2010 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.collect;

import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;

import java.util.ListIterator;

/**
 * A list iterator that does not support {@link #remove}, {@link #add}, or
 * {@link #set}.
 *
 * @since 7
 * @author Louis Wasserman
 */
@Beta
@GwtCompatible
public abstract class UnmodifiableListIterator<E> 
    extends UnmodifiableIterator<E> implements ListIterator<E> {
  /** Constructor for use by subclasses. */
  protected UnmodifiableListIterator(){}
  
  /**
   * Guaranteed to throw an exception and leave the underlying data unmodified.
   *
   * @throws UnsupportedOperationException always
   */
public final void add(E e) {
    throw new UnsupportedOperationException();
  }

  /**
   * Guaranteed to throw an exception and leave the underlying data unmodified.
   *
   * @throws UnsupportedOperationException always
   */
   public final void set(E e) {
    throw new UnsupportedOperationException();
  }
}
